FR3144818A1 - COMPOSITION COMPRISING AT LEAST ONE RECYCLED POLYAMIDE ELASTOMER - Google Patents

Abstract

The present invention relates to a composition comprising at least: (a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups in end of chain, primary amides, nitriles, alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same polyamide elastomer virgin, (b) from 0.1% to 10% by weight of at least one additive, (c) from 0% to 70% by weight of at least one virgin polyamide, (d) from 0% to 65% by weight of at least one load. It also concerns the use of such a composition for the manufacture of objects, as well as the corresponding objects.

Description

COMPOSITION COMPRISING AT LEAST ONE RECYCLED POLYAMIDE ELASTOMER

The present application relates to a composition comprising at least one recycled polyamide elastomer as well as its manufacturing process.

It also concerns the use of such a composition for the manufacture of objects, as well as the corresponding objects.

The circular economy makes it possible to limit waste production, the depletion of the planet's resources and environmental impact. In this context, we seek in particular to promote the recovery (energy or materials) and especially the recycling of waste. This makes it possible to limit final waste as much as possible, that is to say waste which is not capable of being treated under the technical and economic conditions of the moment and which will be incinerated or evacuated to specific storage centers.

By “energy recovery” we mean the use of waste (oils, tires, plastics, etc.) as means of producing energy, by direct incineration with or without other waste.

By “material recovery” we mean reuse or re-use, that is to say the new use of a part which retains the same use and is not transformed.

By “recycling” we mean the operation aimed at introducing materials from waste into the production cycle, as a total or partial replacement for a virgin material.

The present invention relates particularly to the recycling of waste, and aims in particular to propose compositions comprising at least one recycled polyamide elastomer.

There are typically two types of recycled content: post-industrial waste (or post-industrial recycled: PIR) and post-consumer waste (or post-consumer recycled: PCR).

Post-industrial waste (also referred to as “pre-consumer” waste) refers to waste generated either by the manufacturing process that led to the creation of the original source material (manufacturing process such as polymerization and/or compounding for example), or by the manufacturing process which led, in particular starting from an original source material, to the creation of an object such as a sporting article, an article for a motor vehicle such as for example an airplane, a drone, an aircraft, an electric bicycle, a moped, a motorcycle, a side car, a car, a van, a tractor, a truck, a bus, a coach, a snowmobile, a half-track, a bulldozer, a snow groomer and an assault tank, an electronic item for the general public, an item for the medical sector or an item for the industrial sector (injection or extrusion type manufacturing process for example). Post-industrial waste within the meaning of the invention can therefore typically be the injection cores of these different articles or the purge blocks. For the purposes of the invention, parts out of specification or presenting defects likely to prevent their marketing are also considered to be post-industrial waste.

Post-consumer waste corresponds to items, such as those mentioned above, after use by the final consumer or at the end of their life. This is waste that has been used before being discarded, for example having been used for at least one day, for example at least one week, for example at least one month, for example at least one year, for example several years. This waste is typically collected from end users upon disposal, with a view to recycling.

Nowadays, waste management (both post-industrial and post-consumer) as well as the durability of an object are essential for the consumer and have become key requirements, particularly for major sports and electronics brands. This trend increases the interest in having compositions containing at least partly recycled products.

Also, in the context of sustainable consumption and production patterns, the quality of recycled products used in frequently replaced objects such as sporting goods and electronic items for the general public is of particular importance. However, for these articles, the requirements in terms of performance are particularly high.

For these reasons, there is therefore a need to have compositions comprising at least one polyamide elastomer and having a much less significant impact on CO2 emissions.

There is also a need for new compositions comprising at least one recycled polyamide elastomer and retaining good mechanical properties (for example in terms of elasticity, low density, modulus, elongation at break and ability to adhere to different substrates) as well as good processability (suitability for implementation, transformation, in particular by extrusion, by injection, by overmolding, or by welding). In particular, there remains a need for compositions having improved injection processability, in particular a high injection flow length.

The objects obtained from the compositions according to the invention advantageously have sufficient properties to allow their use for high performance applications, and not only for lower performance applications such as street furniture or roads.

In particular, the compositions according to the invention advantageously have better processability and in particular an increase in the flow length during injection molding. This improvement makes it possible to inject thinner parts with better definition.

The compositions according to the invention can also provide better adhesion to other polymers and in particular to polyamides.

The inventors discovered, surprisingly, that the use of recycled polyamide elastomers as defined below, in compositions according to the invention, made it possible to satisfy these needs.

Thus, the invention relates, according to one of its aspects, to a composition comprising at least:

(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide,

(d) from 0% to 65% by weight of at least one filler.

The invention also relates, according to another of its aspects, to the use of a composition according to the invention to give said composition a greater injection flow length compared to the same composition in which the polyamide elastomer is not recycled.

The invention also relates to the use of 30% to 99.9% by weight of at least one recycled polyamide elastomer as defined according to the invention in a composition as defined according to the invention, to give said composition a greater injection flow length compared to the same composition in which the polyamide elastomer is not recycled.

The invention also relates, according to another of its aspects, to the use of a composition according to the invention for the manufacture of objects, in particular mono-materials.

The invention also relates, according to another of its aspects, to an object, in particular a mono-material, consisting of at least 30% by weight, preferably at least 50% by weight, of a composition conforming to the 'invention.

Recycled polyamide elastomer

The recycled polyamide elastomer according to the invention has functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles, alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer.

According to one embodiment, the recycled polyamide elastomer more particularly comprises functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides and nitriles, in a molar ratio relative to the secondary amide functions higher than that of the same virgin polyamide elastomer.

According to the invention, the molar ratio of at least one of the functions resulting from oxidation reactions as defined above with respect to the secondary amide functions is greater for the recycled polyamide elastomer of the invention, in comparison to said molar ratio for the same virgin polyamide elastomer.

This means that if we measure, on the one hand, the molar quantity of one of the functions resulting from oxidation reactions as defined previously and, on the other hand, the molar quantity of the secondary amide functions in the elastomer recycled polyamide of the invention, and that we make the ratio between these two molar quantities (so as to obtain the molar ratio of said function resulting from oxidation reactions in relation to the secondary amide functions for the recycled polyamide elastomer) , said ratio will be greater than that calculated for the same virgin polyamide elastomer (that is to say greater than the ratio between, on the one hand, the molar quantity of one of the functions resulting from oxidation reactions as defined previously and, on the other hand, the molar quantity of secondary amide functions in the same virgin polyamide elastomer).

In particular, according to the invention, the functions resulting from oxidation reactions may be present in the recycled polyamide elastomer of the invention in a molar ratio relative to the secondary amide functions greater than at least 10%, for example greater at least 100%, for example higher by at least 150%, for example higher by at least 300%, compared to that of the same virgin polyamide elastomer.

The molar quantities of the functions resulting from oxidation reactions and the molar quantities of the secondary amide functions (and consequently the molar ratio between these two quantities) can in particular be measured by NMR, for example by proton NMR, in particular depending on the conditions described below.

The compositions of the invention comprise from 30% to 99.9% by weight of at least one recycled polyamide elastomer, relative to the total weight of said composition.

According to one embodiment, the compositions of the invention may comprise from 50 to 99.5% by weight of recycled polyamide elastomer, relative to the total weight of the composition, for example from 70 to 99% by weight, for example from 80 to 98.5% by weight.

As indicated previously, the polyamide elastomer used in the compositions according to the invention is recycled.

By “recycled polyamide elastomer” we mean, within the meaning of the invention, a polyamide elastomer derived from post-industrial waste and/or post-consumer waste, as defined above.

More precisely, in the context of the present invention, the term “post-industrial waste” means waste generated either by the manufacturing process which led to the creation of the original source material, or by the manufacturing process which leads, in particular starting from an original source material, to the creation of an object as defined above, and which have been recycled at least once, preferably at least 2 times, in particular more than 2 times.

According to one embodiment, the recycled polyamide elastomer used in the compositions of the invention can in particular come from post-industrial waste as defined above, which can be recovered for example after a manufacturing step leading to the creation of the material original source or after a manufacturing step leading, in particular starting from an original source material, to the creation of an object such as a sporting article, an article for a motor vehicle such as for example a plane, a drone, an aircraft, an electric bicycle, a moped, a motorcycle, a side car, a car, a van, a tractor, a truck, a bus, a coach, a snowmobile, a half-track, a bulldozer, a snow groomer and an assault tank, an electronic item for the general public, an item for the medical sector or an item for the industrial sector, and which have been recycled at least once, preferably at least 2 times, in particular more than 2 times. These may in particular be scraps which have been melted, that is to say at a temperature higher than their melting temperature (preferably at a temperature higher than at least 20°C, for example 'at least 30°C, for example at least 40°C, for example at least 50°C above their melting temperature). Preferably, these scraps come from extrusion or injection molding processes and have been recycled at least once, preferably at least twice, especially more than twice. It may also be items of poor quality or incapable of fulfilling their function, which are also considered waste, provided that they have been recycled at least once, preferably at least 2 times, in particular more than once. twice. This waste is then generally crushed to be used in a composition of the invention.

According to another embodiment, the recycled polyamide elastomer used in the compositions of the invention can in particular come from post-consumer waste. These may in particular be sporting articles, articles for a motor vehicle such as for example an airplane, a drone, an aircraft, an electric bicycle, a moped, a motorcycle, a side car, a car, a van, a tractor, a truck, a bus, a coach, a snowmobile, a half-track, a bulldozer, a snow groomer and an assault tank, electronic articles for the general public, articles for the medical and/or or used industrial articles which are recovered after purchase and use, preferably use several times, by the final consumer, or when they have reached the end of their life. The term “used” refers to an item that is no longer new, has already been used or has already been used. This expression does not in any way cover post-consumer or post-industrial waste which is recycled without having been used or which has not been used.

According to one embodiment, the recycled polyamide elastomer of the invention does not come from a shoe, in particular from a mono-material shoe.

According to yet another embodiment, the recycled polyamide elastomer used in the compositions of the invention can come from a mixture of post-industrial waste and post-consumer waste as defined above. For example, post-industrial waste can be mixed with post-consumer waste such as sporting goods, items for a motor vehicle such as for example an airplane, a drone, an aircraft, an electric bicycle, a moped , a motorcycle, a side car, a car, a van, a tractor, a truck, a bus, a coach, a snowmobile, a half-track, a bulldozer, a snow groomer and an assault tank, electronic items for the large public, medical articles and/or used industrial articles which are also subsequently crushed.

In a particular embodiment of the invention, the expression “recycled polyamide elastomer” designates only post-industrial waste as defined above. According to this embodiment, the composition of the invention is therefore free of post-consumer waste as defined above.

In another particular embodiment of the invention, the expression “recycled polyamide elastomer” designates only post-consumer waste as defined above. According to this embodiment, the composition of the invention is therefore free of post-industrial waste as defined above.

As mentioned below, the recycled polyamide elastomer used according to the invention is modified compared to a virgin polyamide elastomer. In particular, oxidative stresses during the manufacture of the original source material, its use and/or its subsequent recycling, or even during the manufacture of an object as defined above, its use and/or its subsequent recycling, affect certain of its bonds, such as for example its reactive functions and/or its hydrocarbon chain.

For example, in the case of post-consumer waste (such as glasses or shoes), the objects have generally been exposed during their use, in part or in whole, to conditions likely to affect some of their connections. , these conditions including for example air, in particular oxygen, light, in particular UV rays, or even temperature differences, in particular high temperatures. In the case of sporting goods, the objects may also have been exposed to the perspiration of the people who wore them, to cosmetic products (such as sunscreen), to cleaning products (such as such as, for example, laundry-type detergent products, particularly at temperatures above 30°C), as well as degradation products by microorganisms.

The bonds of polyamide elastomers can also be placed under oxidative stress by multiple processing, granulation and compounding (for example recycling of post-industrial scrap, granulation, compounding and processing after the first life(s) of the material).

Polyamide elastomers thus present particularities, and in particular new species resulting from oxidation mechanisms, when they come from post-industrial waste and/or post-consumer waste as defined previously.

The expression "new species resulting from oxidation mechanisms" is intended to designate, within the meaning of the invention, the formate functions, the methyl groups at the end of the chain, the primary amides, the nitriles, the alkenes, the formamides, the acids carboxylic acids, aldehydes, imides and alcohols which may appear in the recycled polyamide elastomer of the invention.

The recycled polyamide elastomer of the invention has functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles, alkenes, formamides, carboxylic acids, aldehydes, imides and alcohols.

According to a preferred embodiment of the invention, the recycled polyamide elastomer of the invention has functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides and nitriles.

According to a preferred embodiment of the invention, the recycled polyamide elastomer of the invention has functions resulting from oxidation reactions chosen from formate functions and methyl groups at the end of the chain in a molar ratio relative to the functions secondary amides higher than that of the same virgin polyamide elastomer.

These functions can be identified and quantified using infrared spectroscopy and/or proton or carbon NMR.

NMR measurements can be carried out in the HFIP/CD2Cl2 mixture. For example, 20 mg of polymer can be dissolved in 0.7 mL of solvent with an HFIP/CD2Cl2 ratio of 1/3. The dichloromethane (CD2Cl2)/trifluoroacetic anhydride (ATFA) mixture can also be used.

This method is described in the doctoral thesis of E. Goncalves in chapter II.2.3 published in 2011. Analyzes in these two solvents make it possible to identify a majority of functions formed during the life of the polyamide elastomer.

Thus, for example, in infrared spectroscopy, the absorption band from 1700 to 1740 cm-1 corresponds to an imide, that from 1680 to 1720 cm-1 to the carbonyl of the carboxylic acid and that from 3580 to 3670 cm -1 corresponds to the alcohol function of the carboxylic acid.

The absorption band from 3580 to 3670 cm-1 corresponds to the free alcohol function.

The amide function is characterized on the one hand by a pair of absorption bands from 3100 to 3500 cm-1 and from 15560 to 1640 cm-1 which corresponds to the NH group of the amide and on the other hand by the band d absorption from 1650 to 1700 cm-1 which corresponds to the carbonyl group of the amide.

The absorption bands of 1180 and 1723 cm-1 correspond to formates. The bands at 900 and 1660 cm-1 correspond to alkenes.

For example, the degradation of polyethers included in polyamide elastomers, in particular PEBA, can be quantified by infrared spectroscopy by comparing the ratio between the intensities of the band 1111 cm-1 (vibration of the C-O bond of the ether group) or at 2791 cm-1 (CH2 in the α position of the ether function) and the band at 1725 cm-1 (carbonyl function).

Quantification by NMR is, for example, carried out by comparing the intensity of the lines of functions not present in the virgin polymer to the lines corresponding to the CH2 in α of the amide, ether or other CH2 functions in the context of proton NMR. . In carbon NMR, the intensity of the lines of the functions formed during the life of the polymer is compared to the intensities of the carbon lines of amides or CH2.

Some of the functions mentioned above can for example be observed by 13C NMR in the solvent HFIP/CD2Cl2. Thus the line at 36 ppm corresponds to the CH2 at α of the primary amide, that at 34 ppm corresponds to the CH2 at α of the carboxylic acid. These species can be quantified by integrating the area under the lines and comparing them to the area under the line 37.1 ppm corresponding to the secondary amide. Similarly, the lines corresponding to the carbonyl groups of the primary amide, carboxylic acid and secondary amide functions are observed at 181.2 ppm, 179.6 ppm and 177.4 ppm respectively. The line at 16.7 ppm corresponds to CH2 at α of the nitrile group. The formamide group gives a chemical shift at 163.0 ppm and 166.3 ppm.

Other functions mentioned above can be observed in proton NMR (1H NMR) in the solvent HFIP/CD2Cl2 as described above. The line of the CHO groups of the formamides comes out at 7.92 and 8.01 ppm. The line corresponding to CH2 in α of primary amides can be observed at 2.30 ppm. The line at 0.9 ppm corresponds to CH3 groups of the CH3-(CH2)n type. The line at 2.40 ppm corresponds to CH2 in α of the nitrile function. The line corresponding to the proton of the formate function is observed at 8.1 ppm. The line corresponding to the proton of the aldehyde function is observed at 9.7 ppm. Similar to what is described for carbon NMR, the ratios of new functions relative to secondary amides can be determined by integrating the area under the lines and comparing them to the area under the line corresponding to CH2 in α the secondary amide (2.20 ppm) or the area under the line corresponding to the CONH proton of the secondary amide (6.0 – 6.1 ppm).

According to any one of the embodiments of the invention, in a recycled polyamide elastomer of the invention, the molar ratio of the functions resulting from oxidation reactions relative to the secondary amide functions is between 0.0005 and 0, 3.

According to any one of the embodiments of the invention, in a recycled polyamide elastomer of the invention, the molar ratio of the formate functions relative to the secondary amide functions is between 0.0005 and 0.2, in particular between 0.001 and 0.08, especially between 0.005 and 0.05.

According to any one of the embodiments of the invention, in a recycled polyamide elastomer of the invention, the molar ratio of the methyl groups at the end of the chain relative to the secondary amide functions is between 0.0005 and 0.2 , in particular between 0.001 and 0.08, in particular between 0.005 and 0.05.

According to any one of the embodiments of the invention, in a recycled polyamide elastomer of the invention, the molar ratio of the primary amide functions relative to the secondary amide functions is between 0.0005 and 0.1, in particular between 0.001 and 0.08, especially between 0.005 and 0.05.

It is obvious that depending on the waste and the exposure to which it has been subjected, one or more functions resulting from oxidation reactions may be present.

The composition may also include residues of stabilizers chosen from phenols, quinones, stylbenequinones and phosphite.

The recycled polyamide elastomer can also advantageously comprise alkyl chain ends with a carbon number (between 2 and 20, in particular between 8 and 18, for example between 10 and 18) greater than that of a virgin polyamide. Advantageously, the level of alkyl chain ends as defined above can be between 1 ppm and 0.5% by weight relative to the total weight of the polyamide elastomer.

Also, the recycled polyamide elastomers of the invention are generally more colored than the corresponding virgin polyamide elastomers.

The optical properties of recycled and virgin thermoplastic elastomers can be measured according to ISO 53236:2018-02 in reflectance mode on a 2 mm thick plate with the following analysis parameters: observer D65, light beam angle = 10 ° sensor opening = 25 mm and SCI analysis mode. The difference in color between recycled and virgin product is expressed by a ΔE value. According to one embodiment, the recycled polyamide elastomer of the invention has a ΔE value greater than 5, advantageously greater than 10, even preferably greater than 20, compared to the same virgin polyamide elastomer.

The recycled polyamide elastomers of the invention thus advantageously have greater laser absorption, and therefore better weldability and thermoformability, particularly under infrared radiation. To carry out infrared thermoforming, the heating system generally includes two infrared heating plates (upper and lower) to ensure uniform heating. The forming time is of the order of 1s. A pressure of a few bars is applied to obtain good thermoforming.

Compositions comprising recycled polyamide elastomers according to the invention make it possible to carry out thermoforming, in particular under infrared radiation, more quickly than compositions comprising virgin polyamide elastomers. The use of recycled polyamide elastomers of the invention thus advantageously makes it possible to increase productivity.

According to one embodiment, the recycled polyamide elastomer of the invention has a Shore D hardness, as measured according to standard ISO 868:2003, less than or equal to 60, in particular less than or equal to 55, in particular less than or equal to 50.

The recycled polyamide elastomer of the invention is a copolymer with rigid polyamide PA blocks and flexible blocks. It is one of the elastomeric thermoplastic polymers.

The term “thermoplastic elastomeric polymer”, abbreviated “TPE”, designates a polymer which constitutes a polyphasic material having at least two transitions, namely a first transition at a temperature T1 (in general this is the glass transition temperature) and a second transition at a temperature T2 greater than T1 (generally this is the melting point). At a temperature below T1, the material is rigid, between T1 and T2 it behaves elastically, and above T2 it is molten. Such a polymer combines the elastic behavior of rubber-like materials with the processability of thermoplastics.

A thermoplastic elastomer on a polyamide base (TPE-A) within the meaning of the invention, such as a PEBA, is a block copolymer comprising a sequence of blocks, alternately rigid or hard (BD) and flexible or soft (BM), according to the following general formula:

-[BD-BM]n-

and in which:

- BD or Hard Block or rigid block: represents a block comprising polyamide (homopolyamide or copolyamide) or a mixture of blocks comprising polyamide (homopolyamide or copolyamide), hereinafter independently abbreviated PA or BD block;

- BM or Soft Block or flexible block: represents a block based on polyether (PE block), polyester (PES block), polydimethylsiloxane (PDMS block), polyolefin (PO block), polycarbonate (PC block) and /or any other polymer with a low glass transition temperature, or their mixtures in the form of alternating, random or block copolymers. Preferably, BM is a polyether-based block comprising alkylene oxide units, in whole or in part.

- n represents the number of repeating units of the –BD-BM- motif of said copolymer. n is included in the range from 1 to 60, preferably from 5 to 30, or better still from 6 to 20.

By low glass transition temperature for a polymer entering into the composition of a BM within the meaning of the invention, we mean a glass transition temperature Tg lower than 15°C, preferably lower than 0°C, preferably lower than -15°C, preferably even lower than -30°C. For example, said soft block can be based on PEG with a molar mass in number equal to 1500g/mol and Tg of the order of -35°C. Said glass transition temperature Tg can also be lower than -50°C, particularly in the case where said soft block is based on PTMG. The glass transition temperature is measured by dynamic mechanical analysis (DMA) according to the ISO 9721-11:2019 standard by applying a temperature sweep at a rate of 10°C/min.

According to one embodiment, the recycled polyamide elastomer of the invention is a block copolymer comprising at least one rigid polyamide PA block and at least one flexible block, said flexible block comprising at least one block chosen from: polyether, polyester, polydimethylsiloxane, polyolefin, polycarbonate, and their mixtures or copolymers.

According to one embodiment, the recycled polyamide elastomer of the invention is a copolymer with rigid polyamide blocks and flexible polyether blocks (PEBA).

Copolyether block amides, also called copolymers with polyether blocks and polyamide blocks, or abbreviated “PEBA”, result from the polycondensation of polyamide blocks with reactive ends with polyether blocks with reactive ends, such as, among others:

1) polyamide blocks with diamine chain ends with polyoxyalkylene blocks with dicarboxylic chain ends;

2) polyamide blocks with dicarboxylic chain ends with polyoxyalkylene blocks with diamine chain ends, obtained by cyanoethylation and hydrogenation of aliphatic alpha-omega dihydroxylated polyoxyalkylene blocks called polyetherdiols;

3) polyamide blocks with dicarboxylic chain ends with polyetherdiols, the products obtained being, in this particular case, polyetheresteramides.

Polyamide blocks with dicarboxylic chain ends come, for example, from the condensation of polyamide precursors in the presence of a chain-limiting dicarboxylic acid. Polyamide blocks with diamine chain ends come, for example, from the condensation of polyamide precursors in the presence of a chain-limiting diamine.

The molar mass in number Mn of the polyamide blocks is between 400 and 20,000 g/mol and preferably between 500 and 10,000 g/mol.

Polyamide block and polyether block polymers can also include randomly distributed units.

Three types of polyamide blocks can advantageously be used.

According to a first type, the polyamide blocks come from the condensation of a dicarboxylic acid, in particular those having from 4 to 20 carbon atoms, preferably those having from 6 to 18 carbon atoms and an aliphatic or aromatic diamine, in particular those having from 2 to 20 carbon atoms, preferably those having from 6 to 14 carbon atoms.

As examples of dicarboxylic acids, mention may be made of 1,4-cyclohexyldicarboxylic acid, butanedioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic, octadecanedicarboxylic acids and terephthalic and isophthalic acids, but also dimerized fatty acids. .

As examples of diamines, mention may be made of tetramethylene diamine, hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, isomers of bis-(4-aminocyclohexyl)-methane (BACM), bis -(3-methyl-4-aminocyclohexyl)methane (BMACM), and 2-2-bis-(3-methyl-4-aminocyclohexyl)-propane (BMACP), and para-amino-di-cyclohexyl-methane ( PACM), and isophoronediamine (IPDA), 2,6-bis-(aminomethyl)-norbornane (BAMN) and piperazine (Pip).

Concerning the rigid polyamide block, the NF EN ISO 1874-1: 2011 standard defines a nomenclature of polyamides. The term “monomer” in this description must be taken in the sense of “repeating unit”. The case where a repeating unit of the polyamide is constituted by the association of a diacid with a diamine is particular. We consider that it is the combination of a diamine and a diacid, that is to say the “diaminediacid” couple, also known as “XY”, in an equimolar quantity which corresponds to the monomer. This is explained by the fact that individually, the diacid or diamine is only a structural unit, which alone is not sufficient to polymerize.

For example, we have blocks PA412, PA414, PA418, PA610, PA612, PA 613, PA614, PA618, PA912, PA129, PA913, PA1010, PA1012, PA1014, PA 129 and PA1018.

According to a second type, the polyamide blocks result from the condensation of one or more alpha omega aminocarboxylic acids and/or one or more lactams having from 6 to 12 carbon atoms in the presence of a dicarboxylic acid having from 4 to 12 carbon or diamine atoms. Examples of lactams include caprolactam, oenantholactam and lauryllactam. As examples of alpha omega amino carboxylic acid, we can cite aminocaproic, amino-7-heptanoic, amino-11-undecanoic and amino-12-dodecanoic acids.

Advantageously, the polyamide blocks of the second type are made of polyamide 11, polyamide 12 or polyamide 6.

According to a third type, the polyamide blocks result from the condensation of at least one alpha omega aminocarboxylic acid (or a lactam), at least one diamine and at least one dicarboxylic acid.

In this case, the polyamide PA blocks are prepared by polycondensation:

- linear or aromatic aliphatic diamine(s) having X carbon atoms;

- dicarboxylic acid(s) having Y carbon atoms; And

- comonomer(s) {Z}, chosen from lactams and alpha-omega aminocarboxylic acids having Z carbon atoms and equimolar mixtures of at least one diamine having X1 carbon atoms and at least one dicarboxylic acid having Y1 carbon atoms, (X1, Y1) being different from (X, Y);

- said comonomer(s) {Z} being introduced in a weight proportion of up to 50%, preferably up to 20%, even more advantageously up to 10% relative to all the polyamide precursor monomers;

- in the presence of a chain limiter chosen from dicarboxylic acids.

Advantageously, the dicarboxylic acid having Y carbon atoms is used as chain limiter, which is introduced in excess relative to the stoichiometry of the diamine(s).

According to a variant of this third type, the polyamide blocks result from the condensation of at least two alpha omega aminocarboxylic acids or of at least two lactams having 6 to 12 carbon atoms or of a lactam and an n aminocarboxylic acid. not having the same number of carbon atoms in the possible presence of a chain limiter. As an example of aliphatic alpha omega amino carboxylic acid, mention may be made of aminocaproic, amino-7-heptanoic, amino-11-undecanoic and amino-12-dodecanoic acids. As an example of lactam, we can cite caprolactam, oenantholactam and lauryllactam. As an example of aliphatic diamines, we can cite hexamethylenediamine, dodecamethylenediamine and trimethylhexamethylenediamine. As an example of cycloaliphatic diacids, mention may be made of 1,4-cyclohexyldicarboxylic acid. As an example of aliphatic diacids, mention may be made of butane-dioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic acids, dimerized fatty acids (these dimerized fatty acids preferably have a dimer content of at least 98% preferably they are hydrogenated; they are marketed under the brand Pripol® by the company Unichema, or under the brand Empol® by the company Henkel) and polyoxyalkylenes - α,ω diacids. As an example of aromatic diacids, we can cite terephthalic (T) and isophthalic (I) acids. As an example of cycloaliphatic diamines, mention may be made of the isomers of bis-(4-aminocyclohexyl)-methane (BACM), bis-(3-methyl-4-aminocyclohexyl)methane (BMACM), and 2-2-bis -(3-methyl-4-aminocyclohexyl)-propane (BMACP), and para-amino-di-cyclohexyl-methane (PACM). Other commonly used diamines may be isophoronediamine (IPDA), 2,6-bis-(aminomethyl)-norbornane (BAMN), and piperazine.

In the case where the PA blocks of PEBA according to the invention comprise at least two different monomers, called “co-monomers”, that is to say at least one monomer and at least one co-monomer (monomer different from the first monomer) , they include a copolymer such as a copolyamide abbreviated CoPA.

As examples of polyamide blocks of the third type, the following can be cited:

- 66/6 in which 66 designates hexamethylenediamine units condensed with adipic acid. 6 designates patterns resulting from the condensation of caprolactam.

- 66/610/11/12 in which 66 designates hexamethylenediamine condensed with adipic acid. 610 designates hexamethylenediamine condensed with sebacic acid. 11 designates units resulting from the condensation of aminoundecanoic acid. 12 designates patterns resulting from the condensation of lauryllactam.

The mass Mn of the flexible blocks is between 100 and 6,000 g/mol and preferably between 200 and 3,000 g/mol.

Preferably, the polymer comprises from 1 to 80% by mass of flexible blocks and from 20 to 99% by mass of polyamide blocks, preferably from 4 to 80% by mass of flexible blocks and 20 to 96% by mass of polyamide blocks. .

According to a preferred embodiment, the rigid polyamide block, in the copolymer with rigid PA blocks and flexible blocks according to the invention, comprises at least one of the following polyamide units: 11, 12, 6, 610, 612, 613, 129 , 913, 1010, 1012, and their mixtures or copolyamides.

According to one embodiment, the recycled polyamide elastomer of the invention is a block copolymer comprising at least one rigid polyamide PA block and at least one flexible block, said flexible block comprising at least one PE polyether, preferably chosen from PTMG , PPG, PO3G and/or PEG, in particular as defined below.

PE polyether blocks are made up of alkylene oxide units. These units can be, for example, ethylene oxide units, propylene oxide units or tetrahydrofuran units (which leads to polytetramethylene glycol sequences). We thus use PEG (polyethylene glycol) blocks, i.e. those made up of ethylene oxide units, PPG (propylene glycol) blocks, i.e. those made up of propylene oxide units, PO3G (polytrimethylene glycol) blocks. ) that is to say those made up of polytrimethylene ether glycol units (such copolymers with polytrimethylene ether blocks are described in document US6590065), and PTMG blocks that is to say those made up of tetramethylene glycol units also called polytetrahydrofuran. PEBA copolymers can include several types of polyethers in their chain, the copolyethers being able to be block or random.

It is also possible to use blocks obtained by oxyethylation of bisphenols, such as for example bisphenol A. These latter products are described in patent EP613919.

The polyether blocks can also be made up of ethoxylated primary amines. As an example of ethoxylated primary amines, we can cite the products of formula:
[Chem 1]

in which m and n are between 1 and 20 and x between 8 and 18. These products are commercially available under the brand Noramox® from the company CECA and under the brand Genamin® from the company Clariant.

The flexible polyether blocks may comprise polyoxyalkylene blocks with NH ₂ chain ends, such blocks being obtainable by cyanoacetylation of aliphatic alpha-omega dihydroxylated polyoxyalkylene blocks called polyetherdiols. More particularly, Jeffamines can be used (for example Jeffamine® D400, D2000, ED 2003,

The polyetherdiol blocks are either used as is and copolycondensed with polyamide blocks with carboxylic ends, or they are aminated to be transformed into polyether diamines and condensed with polyamide blocks with carboxylic ends. The general two-step preparation method for PEBA copolymers having ester bonds between the PA blocks and the PE blocks is known and is described, for example, in French patent FR2846332. The general method for preparing the PEBA copolymers of the invention having amide bonds between the PA blocks and the PE blocks is known and described, for example in European patent EP1482011. Polyether blocks can also be mixed with polyamide precursors and a diacid chain limiter to make polyamide block and polyether block polymers having statistically distributed units (one-step process).

Of course, the designation PEBA in the present description of the invention relates equally to Pebax® marketed by Arkema, to Vestamid® marketed by Evonik®, to Grilamid® marketed by EMS, to Kellaflex® marketed by DSM or to any other PEBA from other suppliers.

Advantageously, the PEBA copolymers have PA blocks in PA 6, PA 11, PA 12, PA 612, PA 613, PA 912, PA 129, PA 913, PA 66/6, PA 1010 and /or PA 614, preferably PA 11 and/or PA 12 blocks; and PE blocks in PTMG, PPG and/or PO3G. PEBAs based on PE blocks consisting mainly of PEG are included in the range of hydrophilic PEBAs. PEBAs based on PE blocks consisting mainly of PTMG are included in the range of hydrophobic PEBAs.

Advantageously, said PEBA used in the composition according to the invention is obtained at least partially from bio-resourced raw materials.

By raw materials of renewable origin or bio-resourced raw materials, we mean materials which include bio-resourced carbon or carbon of renewable origin. Indeed, unlike materials derived from fossil materials, materials composed of renewable raw materials contain ¹⁴ C. The “carbon content of renewable origin” or “bio-resourced carbon content” is determined in accordance with the standards ASTM D 6866 (ASTM D 6866-06) and ASTM D 7026 (ASTM D 7026-04). For example, PEBA based on polyamide 11 come at least in part from bio-resourced raw materials and have a bio-resourced carbon content of at least 1%, which corresponds to an isotopic ratio of ¹² C. / ¹⁴ C of at least 1.2 x 10 ¹⁴ . Preferably, the PEBAs according to the invention comprise at least 50% by mass of bio-resourced carbon on the total mass of carbon, which corresponds to a ¹² C/ ¹⁴ C isotopic ratio of at least 0.6.10 ^-12 . This content is advantageously higher, in particular up to 100%, which corresponds to a ¹² C/ ¹⁴ C isotopic ratio of 1.2 x 10 ^-12 , in the case for example of PEBA with PA 11 blocks and PE blocks comprising PO3G, PTMG and/or PPG from raw materials of renewable origin.

PES polyester blocks are usually manufactured by polycondensation between a dicarboxylic acid and a diol. Suitable carboxylic acids include those mentioned above used to form the polyamide blocks with the exception of terephthalic and isophthalic acids. Suitable diols include linear aliphatic diols such as ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexylene glycol, branched diols such as neopentyl glycol, 3- methylpentane glycol, 1,2-propylene glycol, and cyclic diols such as 1,4-bis(hydroxymethyl)cyclohexane and 1,4-cyclohexane-dimethanol.

By polyesters we also mean poly(caprolactone) and PES based on fatty acid dimers, in particular products from the PRIPLAST® range from the company Croda or Uniqema.

We can also consider a PES block of alternating “copolyester” type, statistical or block, containing a sequence of at least two types of PES cited above.

By polysiloxane block (hereinafter abbreviated PSi) within the meaning of the invention, is meant any organized polymer or oligomer with a linear or cyclic, branched or crosslinked structure obtained by polymerization of functionalized silanes and essentially constituted by a repetition of units principal in which silicon atoms are linked together by oxygen atoms (Si-O-Si siloxane bond), optionally substituted hydrocarbon radicals being directly linked via a carbon atom to said silicon atoms . The most common hydrocarbon radicals are alkyl radicals in particular C1-C10 and in particular methyl, fluoroalkyl radicals, aryl radicals and in particular phenyl, and alkenyl radicals and in particular vinyl; other types of radicals capable of being linked either directly, or via a hydrocarbon radical, to the siloxane chain are in particular hydrogen, halogens and in particular chlorine, bromine or fluorine, thiols, alkoxy radicals, polyoxyalkylene (or polyethers) radicals and in particular polyoxyethylene and/or polyoxypropylene, hydroxyl or hydroxyalkyl radicals, substituted or unsubstituted amine groups, amide groups, acyloxy or acyloxyalkyl radicals, hydroxyalkylamino or aminoalkyl radicals , quaternary ammonium groups, amphoteric or betaine groups, anionic groups such as carboxylates, thioglycolates, sulfosuccinates, thiosulfates, phosphates and sulfates, and their mixtures, this list being of course in no way restrictive (so-called "organomodified" silicones).

Preferably, said polysiloxane blocks comprise polydimethylsiloxane (hereinafter abbreviated PDMS blocks), polymethylphenylsiloxane, and/or polyvinylsiloxane.

By polyolefin block (hereinafter abbreviated PO block) within the meaning of the invention, is meant any polymer comprising as monomer an alpha-olefin, that is to say homopolymers of an olefin or copolymers of at least an alpha-olefin and at least one other copolymerizable monomer, the alpha-olefin advantageously having from 2 to 30 carbon atoms.

As an example of alpha-olefin, mention may be made of ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3 -methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, 1-dococene, 1-tetracocene, 1-hexacocene, 1-octacocene , and 1-triacontene. These alpha-olefins can be used alone or in a mixture of two or more.

As examples, we can cite:

- homopolymers and copolymers of ethylene, in particular low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), polyethylene obtained by metallocene catalysis;

- propylene homopolymers and copolymers,

- essentially amorphous or attactic polyalphaolefins (APAO),

- ethylene/alpha-olefin copolymers such as ethylene/propylene, EPR (ethylene-propylene-rubber) elastomers, and EPDM (ethylene-propylene-diene), and blends of polyethylene with an EPR or an EPDM,

- styrene/ethylene-butene/styrene (SEBS), styrene/butadiene/styrene (SBS), styrene/isoprene/styrene (SIS), and styrene/ethylene-propylene/styrene (SEPS) block copolymers,

- copolymers of ethylene with at least one product chosen from salts or esters of unsaturated carboxylic acids such as for example alkyl (meth)acrylates, the alkyl being able to have up to 24 carbon atoms, vinyl esters of saturated carboxylic acids such as for example vinyl acetate or propionate, and dienes such as for example 1,4-hexadiene or polybutadiene.

According to an advantageous embodiment of the invention, said at least one polyolefin block comprises polyisobutylene and/or polybutadiene.

According to a particularly advantageous embodiment, the block copolymer according to the invention comprises at least one flexible polyolefin block (PO block) and at least one hard hydrophilic block (hereinafter abbreviated BDh) comprising both polyamide and polyether, such as a polyetheramide block, a polyetheresteramide block, and/or a polyetheramideimide block, etc. Said PO block preferably comprises a polyolefin comprising acid, alcohol or amine terminal groups. Preferably, the PO block is obtained by thermal degradation of high molecular weight polyolefins to form lower mass and functionalized polyolefins (reference method: Japanese Kokai Publication Hei-03-62804). With regard to the BDh block, it may further comprise at least one polymer chosen from: cationic polymers, of the quaternary amine type and/or phosphorus derivatives; and/or anionic polymers, of the modified diacid type, comprising a sulfonate group and capable of reacting with a polyol. The addition of organic salt is then possible in the preparation of the BDh block or during the reaction between the PO block and the BDh block. Document US6552131 describes the synthesis and the different possible structures for the copolymer with PO blocks and BDh blocks, these being of course possible in the process according to the invention.

By polycarbonate block (hereinafter abbreviated PC block) within the meaning of the invention, we mean more particularly any aliphatic polycarbonate. Aliphatic polycarbonates are described for example in documents DE2546534 and JP1009225. Such homopolymer or copolymer polycarbonates are also described in document US471203. Applications WO92/22600 and WO95/12629 describe copolymers comprising polycarbonate blocks as well as their synthesis processes. The blocks (and their synthesis) described in these documents are perfectly conceivable for the synthesis of a PC block copolymer according to the invention. Preferably, the polycarbonate blocks of the copolymer according to the invention have the formula:

in which a is an integer from 2 to 300; R1 and R2, which may be identical or different, represent a straight or branched, aliphatic or alicyclic chain having 2 to 18 carbon atoms, or represent a polyoxyalkylene group or even represent a polyester group.

Polycarbonates in which R1 and R2 are chosen from the groups hexylene, decylene, dodecylene, 1,4-cyclohexylene, 2,2-dimethyl1,3-propylene, 2,5-dimethyl-2,5-hexylene or polyoxyethylene are preferred.

If the block copolymers described above generally comprise at least one rigid polyamide block and at least one flexible block, it is obvious that the present invention in fact covers all copolymers comprising two, three, four (or even more) different blocks chosen among those described in the present description, as long as at least one of these blocks is a polyamide block.

Advantageously, the copolymer according to the invention comprises a segmented block copolymer comprising three different types of blocks (called “triblock” in the present description of the invention), which result from the condensation of several of the blocks described above. Said triblock is preferably chosen from copolyetheresteramides, copolyetheramideurethanes, in which:

- the mass percentage of rigid polyamide block is greater than 10%;

- the mass percentage of flexible blocks is greater than 20%;

on the total triblock mass.

According to a preferred embodiment, the flexible block in the copolymer with rigid blocks PA and flexible blocks according to the invention, comprises (and preferably is) a polyether block PE, preferably chosen from PTMG, PPG, PO3G and/or PEG .

According to another advantageous embodiment, the flexible block in the copolymer with rigid blocks PA and flexible blocks according to the invention, comprises (and preferably is) a polyester block PES, chosen from polyester diols, poly (caprolactone) and polyesters based on fatty acid dimers.

Advantageously, in the copolymer according to the invention, the ratio by weight of the PA blocks to the flexible blocks is in the range from 0.3 to 10, preferably from 0.3 to 6, preferably from 0.3 to 3 , preferably from 0.3 to 2.

Preferably, said copolymer according to the invention comprises from 45 to 75% by weight of flexible polytetramethylene glycol (PTMG) blocks, preferably from 50 to 70% by weight of PTMG blocks, on the total weight of copolymer.

Preferably, said PA polyamide block of the copolymer of the invention comprises at least one of the following polyamide units: 6, 66, 610, 612, 613, 129, 913 PA1010, PA1012, PA11, PA12, PA6/12, and their mixtures or copolyamides.

Advantageously, the copolymer comprises a copolymer with rigid polyamide blocks and flexible polyether blocks (PEBA), preferably chosen from the following PEBAs: PA6-PTMG, PA1010-PTMG, PA1012-PTMG, PA11-PTMG, PA12-PTMG, PA6/12 -PTMG, PA66-PTMG, PA613-PTMG, PA129-PTMG, PA913-PTMG and their mixtures.

According to any one of the embodiments, the polyamide of the rigid block of the recycled polyamide elastomer according to the invention can have a C/N ratio greater than 6.5, advantageously greater than 7.5, preferably greater than 8 ,5.

Additives

Said recycled polyamide elastomer, whether it comes from post-industrial waste or post-consumer waste as defined above, comes from grades of aliphatic polyamides which may possibly include additives.

As indicated above, the compositions according to the invention comprise at least 0.1% by weight of at least one additive, relative to the total weight of said composition.

It is specified that the additive considered according to the invention is an additive which has been expressly added in a content of at least 0.1% by weight, relative to the total weight of the composition, to the recycled polyamide elastomer for obtain a composition of the invention.

In other words, the additives which may already be present in the recycled polyamide elastomer are not taken into consideration in the context of the present invention.

The compositions of the invention may in particular comprise from 0.1% to 10% by weight of additives, relative to the total weight of said composition, in particular from 0.3% to 6% by weight, for example from 0.5 % to 2% by weight.

The additives present in the compositions of the invention are the conventional additives used and well known to those skilled in the art.

According to one embodiment, it may in particular be at least one additive chosen from a catalyst, an antioxidant, a heat stabilizer, a UV absorber, a light stabilizer, a lubricant, a nucleating agent , a dye, a wax and mixtures thereof.

The term “catalyst” designates a polycondensation catalyst such as a mineral or organic acid.

Advantageously, the proportion by weight of catalyst is comprised from approximately 50 ppm to approximately 5000 ppm, in particular from approximately 100 to approximately 3000 ppm relative to the total weight of the composition.

Advantageously, a derivative of a metal chosen from the group formed by titanium, zirconium and hafnium or a strong acid such as phosphoric acid, hypophosphorous acid or boric acid is used as catalyst.

For example, the stabilizer may be a UV stabilizer, an organic stabilizer or more generally a combination of organic stabilizers, such as a phenol type antioxidant (for example of the type of irganox® 245 or 1098 or 1010 of the company Ciba-BASF), a phosphite-type antioxidant (for example irgafos® 126 and irgafos® 168 from the company Ciba-BASF) and possibly other stabilizers such as a HALS, which means Hindered Amine Light Stabilize or hindered amine type light stabilizer (for example Tinuvin® 770 from the company Ciba-BASF), an anti-UV (for example Tinuvin® 312 from the company Ciba) or a phosphorus-based stabilizer. It is also possible to use amine-type antioxidants such as Naugard® 445 from the Crompton company or even polyfunctional stabilizers such as Nylostab® S-EED from the Clariant company.

This stabilizer can also be a mineral stabilizer, such as a copper-based stabilizer. As an example of such mineral stabilizers, mention may be made of copper halides and acetates. Incidentally, we can possibly consider other metals such as silver, but these are known to be less effective. These copper-based compounds are typically associated with alkali metal halides, particularly potassium.

Virgin polyamide

The compositions according to the invention may also comprise at least one virgin polyamide.

By “virgin polyamide”, we mean, within the meaning of the invention, a polyamide which is not recycled, that is to say a polyamide which does not come from post-industrial waste and/or post-consumer waste, as defined above.

In particular, the compositions of the invention may comprise from 0% to 70% by weight of at least one virgin polyamide, relative to the total weight of said composition.

According to one embodiment, the compositions of the invention may comprise from 0.1 to 50% by weight of at least one virgin polyamide, relative to the total weight of the composition, for example from 0.2 to 35% by weight. weight, for example from 5 to 25% by weight.

According to any of the embodiments of the invention, the virgin polyamide can be chosen from homopolyamides, copolyamides, and copolymers with polyamide blocks and polyether blocks (PEBA) or their mixtures.

According to one embodiment, the virgin polyamide can also be a mixture of polyamide and at least one other polymer, the polyamide forming the matrix and the other polymer(s) forming the dispersed phase.

Preferably, the virgin polyamide can be a condensation product:

- one or more amino acids;

- one or more lactams; Or

- one or more salts or mixtures of diamines with diacids.

As an example of an amino acid, it is possible to cite alpha-omega amino acids, such as aminocaproic, 7-aminoheptanoic, 11-aminoundecanoic, n-heptyl-11-aminoundecanoic and 12-amino acids. -dodecanoeic.

Lactam monomers preferably comprise between 3 and 12 carbon atoms on the main ring and may be substituted. As an example of lactam, it is possible to cite β, β-dimethylpropriolactam, α, α-dimethylpropriolactam, amylolactam, caprolactam, capryllactam, oenantholactam, 2-pyrrolidone and lauryllactam.

Preferably the diamine used in the composition of the virgin polyamide is an aliphatic diamine, an aryl diamine and/or a saturated cyclic diamine having from 6 to 12 carbon atoms. As an example of a diamine, it is possible to cite hexamethylenediamine, decanediamine, piperazine, tetramethylenediamine, octamethylenediamine, decamethylenediamine, dodecamethylenediamine, 1,5 diaminohexane, 2,2 ,4-trimethyl-1,6-diamino-hexane, diamine polyols, isophorone diamine (IPD), methyl-pentamethylenediamine (MPDM), bis(aminocyclohexyl)methane (BACM), bis(3-methyl- 4 aminocyclohexyl)methane (BMACM), methaxylenediamine, bis-p-aminocyclohexylmethane and trimethylhexamethylenediamine.

Preferably, the dicarboxylic acid used in the composition of the virgin polyamide has between 4 and 18 carbon atoms. As an example of a dicarboxylic acid, it is possible to cite adipic acid, sebacic acid, azelaic acid, suberic acid, isophthalic acid, butanedioic acid, 1,4 acid. cyclohexyldicarboxylic acid, terephthalic acid, the sodium or lithium salt of sulfo-isophthalic acid, dimerized fatty acids (these dimerized fatty acids have a dimer content of at least 98% and are preferably hydrogenated) and dodecanedioic acid HOOC-(CH ₂ )10-COOH.

Preferably, the virgin copolyamide results from the condensation of at least two different monomers, for example of at least two different alpha-omega aminocarboxylic acids or of two different lactams or of a lactam and an alpha-omega aminocarboxylic acid of different carbon numbers. It is also possible to cite copolyamides resulting from the condensation of at least one alpha-omega aminocarboxylic acid (or a lactam), at least one diamine and at least one dicarboxylic acid. It is also possible to cite the copolyamides resulting from the condensation of an aliphatic diamine with an aliphatic dicarboxylic acid and at least one other monomer chosen from aliphatic diamines different from the previous one and aliphatic diacids different from the previous one.

Preferably, the virgin polyamide may comprise at least one polyamide or copolyamide comprising at least one monomer selected from the group consisting of 46, 4T, 54, 59, 510, 512, 513, 514, 516, 518, 536, 6, 64 , 66, 69, 610, 612, 613, 614, 616, 618, 636, 6T, 9, 913, 104, 109, 1010, 1011, 1012, 1013, 1014, 1016, 1018, 1036, 10T, , 12 , 124, 129, 1210, 1212, 1213, 1214, 1216, 1218, 1236, 12T, MXD6, MXD10, MXD12, MXD14, and mixtures thereof.

Preferably, the virgin polyamide is selected from the group consisting of PA 6, PA 66, PA 1010, PA 11, PA 12, PA 1011, PA 610, PA612, PA 613 and mixtures thereof. .

As an example of copolyamide, it is possible to cite copolymers of caprolactam and lauryllactam (PA 6/12), copolymers of caprolactam, adipic acid and hexamethylene diamine (PA 6/66), copolymers of caprolactam, lauryllactam, adipic acid and hexamethylene diamine (PA 6/12/66), copolymers of caprolactam, lauryllactam, amino-11-undecanoic acid, azelaic acid and hexamethylene diamine (PA 6/69/11/12), copolymers of caprolactam, lauryllactam, 11-aminoundecanoic acid, adipic acid and hexamethylene diamine (PA 6/66/11/12), copolymers lauryllactam, azelaic acid and hexamethylene diamine (PA 69/12), copolymers of amino-11-undecanoic acid, terephthalic acid and decamethylene diamine (PA 11/10T).

Preferably, the average number of carbon atoms (C) relative to the nitrogen atom (N) (i.e. the C/N ratio) of the virgin polyamide is greater than 6.5, advantageously greater than 7.5 , preferably greater than 8.5, in particular greater than or equal to 10, preferably greater than or equal to 11. Particularly preferably, the average number of carbon atoms (C) relative to the nitrogen atom (N) virgin polyamide is 11 or 12.

Preferably, the virgin polyamide is chosen from PA 11, PA 1010, PA 1012, PA 12, PA 1212, PA 1014 or PA 1214 and their mixtures, preferably PA11 or PA12 or a mixture of these.

It may also be a copolymer with polyamide blocks and polyether blocks (PEBA), as defined previously.

Preferably, the polyamide of the rigid block of said PEBA can have a C/N ratio greater than 6.5, advantageously greater than 7.5, preferably greater than 8.5.

The nomenclature used to define polyamides is described in standard ISO 1874-1:2010 "Plastics -- Polyamide (PA) materials for molding and extrusion -- Part 1: Designation", in particular on page 3 (tables 1 and 2) and is well known to those skilled in the art.

According to a preferred embodiment of the invention, the polyamide of the rigid block of the polyamide elastomer of the invention and the virgin polyamide (or the polyamide block of the virgin PEBA) have the same C/N ratio. For example, the polyamide of the rigid block of the polyamide elastomer of the invention may be PA11 and the virgin polyamide (or the polyamide block of the virgin PEBA) may be PA1012.

According to another preferred embodiment of the invention, the polyamide of the rigid block of the polyamide elastomer of the invention and the virgin polyamide (or the polyamide block of the virgin PEBA) are of identical nature. For example, the polyamide of the rigid block of the polyamide elastomer of the invention may be PA12 and the virgin polyamide (or the polyamide block of the virgin PEBA) may be PA12.

According to yet another embodiment of the invention, the difference between on the one hand the C/N ratio of the polyamide of the rigid block of the polyamide elastomer of the invention and on the other hand the C/N ratio of the polyamide virgin (or the polyamide block of virgin PEBA) can be less than or equal to 3, in particular less than or equal to 2, in particular less than or equal to 1. For example, the polyamide of the rigid block of the polyamide elastomer of the invention can be PA12 and the virgin polyamide (or the polyamide block of virgin PEBA) can be PA11. According to another example, the polyamide of the rigid block of the polyamide elastomer of the invention may be PA12 and the virgin polyamide (or the polyamide block of the virgin PEBA) may be PA11.

According to one embodiment, the polyamide elastomer of the invention and the virgin polyamide are of identical nature. For example, the polyamide elastomer of the invention and the virgin polyamide can both be PEBAs as defined above.

According to one embodiment of the invention, the virgin polyamide preferably has an inherent viscosity greater than or equal to 1.10 dL/g, in particular greater than or equal to 1.15 dL/g.

For example, the virgin polyamide may have an inherent viscosity of between 1.1 dL/g and 1.65 dL/g, for example between 1.2 dL/g and 1.55 dL/g.

The inherent viscosity is determined in m-cresol according to the ISO 307:2007 standard but by changing the solvent (use of m-cresol instead of sulfuric acid and the temperature being 20°C).

Shock modifier

The compositions according to the invention may also comprise at least one impact modifier.

In particular, the compositions of the invention may comprise from 0% to 30% by weight of at least one impact modifier, relative to the total weight of said composition.

According to one embodiment, the compositions of the invention may comprise from 1 to 25% by weight of at least one impact modifier, relative to the total weight of the composition, for example from 3 to 20% by weight, for example from 6 to 15% by weight.

The impact modifier is advantageously constituted by a polymer having a flexural modulus less than 100 MPa measured according to the ISO 178: 2010 standard, determined at 23°C with a relative humidity: RH50%, and a Tg less than 0°C (measured according to standard 11357-2:2013 at the level of the inflection point of the DSC thermogram, at a heating rate of 20K/min), in particular a polyolefin.

The polyolefin of the impact modifier may be functionalized or non-functionalized or be a mixture of at least one functionalized and/or at least one non-functionalized. For simplicity, the polyolefin has been designated by (B) and functionalized polyolefins (B1) and non-functionalized polyolefins (B2) have been described below.

A non-functionalized polyolefin (B2) is conventionally a homopolymer or copolymer of alpha olefins or diolefins, such as for example ethylene, propylene, butene-1, octene-1, butadiene. As an example, we can cite:

- homopolymers and copolymers of polyethylene, in particular LDPE, HDPE, LLDPE (linear low density polyethylene, or linear low density polyethylene), VLDPE (very low density polyethylene, or very low density polyethylene) and metallocene polyethylene,

-propylene homopolymers or copolymers,

- ethylene/alpha-olefin copolymers such as ethylene/propylene, EPR (abbreviation of ethylene-propylene-rubber) and ethylene/propylene/diene (EPDM),

- styrene/ethylene-butene/styrene (SEBS), styrene/butadiene/styrene (SBS), styrene/isoprene/styrene (SIS), styrene/ethylene-propylene/styrene (SEPS) block copolymers,

- copolymers of ethylene with at least one product chosen from salts or esters of unsaturated carboxylic acids such as alkyl (meth)acrylate (for example methyl acrylate), or vinyl esters of carboxylic acids saturated such as vinyl acetate (EVA), the proportion of comonomer being able to reach 40% by weight.

The functionalized polyolefin (B1) may be a polymer of alpha olefins having reactive units (the functionalities); such reactive units are acid, anhydride, or epoxy functions. By way of example, mention may be made of the preceding polyolefins (B2) grafted or co- or ter polymerized with unsaturated epoxides such as glycidyl (meth) acrylate, or with carboxylic acids or the corresponding salts or esters such as (meth)acrylic acid (this can be totally or partially neutralized by metals such as Zn, etc.) or by carboxylic acid anhydrides such as maleic anhydride. A functionalized polyolefin is for example a PE/EPR mixture, the weight ratio of which can vary widely, for example between 40/60 and 90/10, said mixture being co-grafted with an anhydride, in particular maleic anhydride, according to a grafting rate for example of 0.01 to 5% by weight.

The functionalized polyolefin (B1) can be chosen from the following (co)polymers, grafted with maleic anhydride or glycidyl methacrylate, in which the grafting rate is for example 0.01 to 5% by weight:

- PE, PP, copolymers of ethylene with propylene, butene, hexene, or octene containing for example 35 to 80% by weight of ethylene;

- ethylene/alpha-olefin copolymers such as ethylene/propylene, EPR (abbreviation of ethylene-propylene-rubber) and ethylene/propylene/diene (EPDM),

- styrene/ethylene-butene/styrene (SEBS), styrene/butadiene/styrene (SBS), styrene/isoprene/styrene (SIS), styrene/ethylene-propylene/styrene (SEPS) block copolymers,

- ethylene and vinyl acetate copolymers (EVA), containing up to 40% by weight of vinyl acetate;

- ethylene and alkyl (meth)acrylate copolymers, containing up to 40% by weight of alkyl (meth)acrylate;

- ethylene and vinyl acetate (EVA) and alkyl (meth)acrylate copolymers, containing up to 40% by weight of comonomers.

The functionalized polyolefin (B1) can also be chosen from ethylene/propylene copolymers with a majority of propylene grafted with maleic anhydride then condensed with monoamine polyamide (or a polyamide oligomer) (products described in EP-A-0342066) .

The functionalized polyolefin (B1) can also be a co- or ter polymer of at least the following units: (1) ethylene, (2) alkyl (meth)acrylate or vinyl ester of saturated carboxylic acid and (3) anhydride such as maleic anhydride or (meth)acrylic or epoxy acid such as glycidyl (meth)acrylate.

As an example of functionalized polyolefins of the latter type, the following copolymers may be cited, where ethylene preferably represents at least 60% by weight and where the ter monomer (the function) represents for example from 0.1 to 10% by weight of the copolymer:

- ethylene/alkyl (meth)acrylate/(meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers;

- ethylene/vinyl acetate/maleic anhydride or glycidyl methacrylate copolymers;

- ethylene/vinyl acetate or alkyl (meth)acrylate/(meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers.

In the above copolymers, the (meth)acrylic acid can be salified with Zn or Li.

The term "alkyl (meth)acrylate" in (B1) or (B2) denotes C1 to C8 alkyl methacrylates and acrylates, and can be chosen from methyl acrylate, ethyl acrylate , n-butyl acrylate, iso-butyl acrylate, ethyl-2-hexyl acrylate, cyclohexyl acrylate, methyl methacrylate and ethyl methacrylate.

Furthermore, the aforementioned polyolefins (B1) can also be crosslinked by any appropriate process or agent (diepoxy, diacid, peroxide, etc.); the term functionalized polyolefin also includes mixtures of the aforementioned polyolefins with a difunctional reagent such as diacid, dianhydride, diepoxy, etc. capable of reacting with these or mixtures of at least two functionalized polyolefins capable of reacting with each other.

The copolymers mentioned above, (B1) and (B2), can be copolymerized randomly or block-wise and have a linear or branched structure.

The molecular weight, the MFI index, the density of these polyolefins can also vary to a large extent, which those skilled in the art will appreciate. MFI, short for Melt Flow Index, is the melt flow index. It is measured according to the ASTM 1238 standard.

Advantageously, the non-functionalized polyolefins (B2) are chosen from homopolymers or copolymers of polypropylene and any homopolymer of ethylene or copolymer of ethylene and a higher alpha olefin type comonomer such as butene, hexene, octene or 4-methyl 1-Pentene. We can cite for example PP, high density PE, medium density PE, linear low density PE, low density PE, very low density PE. These polyethylenes are known by those skilled in the art as being produced according to a “radical” process, according to “Ziegler” type catalysis or, more recently, according to so-called “metlocene” catalysis.

Advantageously, the functionalized polyolefins (B1) are chosen from any polymer comprising alpha olefinic units and units carrying polar reactive functions such as epoxy, carboxylic acid or carboxylic acid anhydride functions. As examples of such polymers, mention may be made of ter polymers of ethylene, alkyl acrylate and maleic anhydride or glycidyl methacrylate such as Lotader® from SK Functional Polymer or polyolefins grafted with maleic anhydride such as Orevac® from SK Functional Polymer as well as ter polymers of ethylene, alkyl acrylate and (meth)acrylic acid. Mention may also be made of polypropylene homopolymers or copolymers grafted with a carboxylic acid anhydride then condensed with polyamides or monoamino polyamide oligomers.

Charge

The compositions according to the invention may also comprise at least one filler.

In particular, the compositions of the invention may comprise from 0% to 65% by weight of at least one filler, relative to the total weight of said composition.

According to one embodiment, the compositions of the invention may comprise from 2 to 30% by weight of at least one filler, relative to the total weight of the composition, for example from 5 to 25% by weight, for example from 6 to 20% by weight.

The charges can be chosen from:

- The reinforcing fibers can be chosen from glass fibers, carbon fibers, natural fibers (wood, linen, cellulose, hemp, etc.)

- Current-conducting fillers such as carbon black and carbon nanotubes

- Flame retardants (HFFR)

- Fillers making it possible to reduce the density of the composition such as glass beads, particularly hollow ones

- Heat-conducting fillers chosen from metal oxides (Al2O3, Al2SiO5, etc.), ceramics (BN, AlN, etc.)

According to one embodiment, a composition of the invention may in particular comprise reinforcing fibers, which are in particular fibers of mineral, organic or plant origin.

Said reinforcing fiber can be sized or unsized.

Said reinforcing fiber can therefore comprise up to 0.1% by weight of a material of an organic nature (thermosetting or thermoplastic resin type) called sizing.

Among the fibers of mineral origin, we can cite carbon fibers, glass fibers, basalt fibers or basalt-based fibers, silica fibers, or silicon carbide fibers for example. Among the fibers of organic origin, we can cite fibers based on thermoplastic or thermosetting polymer, such as semi-aromatic polyamide fibers, aramid fibers or polyolefin fibers for example. Among the fibers of plant origin, we can cite natural fibers based on flax, hemp, lignin, bamboo, silk in particular spider silk, sisal, and other cellulosic fibers, in particular viscose. These fibers of plant origin can be used pure, treated or coated with a coating layer, in order to facilitate adhesion and impregnation of the thermoplastic polymer matrix.

Preferably said reinforcing fiber is chosen from glass fibers, carbon fibers, basalt fibers and basalt-based fibers.

More advantageously, said reinforcing fiber is chosen from carbon fibers and glass fibers.

In one embodiment, the reinforcing fibers present in a) are glass fibers.

The glass fibers can be circular or non-circular in section. Advantageously, the glass fibers are circular. The glass fibers are in particular of type E, R, S2, or T. Advantageously the glass fibers are of type E.

In one embodiment, the fillers are recycled. For fillers comprising glass, they may in particular be manufactured from industrial production waste or post-consumer glass. Carbon fibers can, for example, come from cutting spools of expired long fibers, in particular carbon fibers for aeronautics.

Plasticizers

The compositions according to the invention may also comprise at least one plasticizer.

In particular, the compositions of the invention may comprise from 0% to 15% by weight of at least one plasticizer, relative to the total weight of said composition.

According to one embodiment, the compositions of the invention may comprise from 4% to 13% by weight of at least one plasticizer, relative to the total weight of the composition, for example from 6% to 12% by weight.

The plasticizers are, for example, the plasticizers are chosen from benzene sulfonamide derivatives, such as n-butyl benzene sulfonamide (BBSA); ethyl toluene sulfonamide or N-cyclohexyl toluene sulfonamide; esters of hydroxybenzoic acids, such as ethyl-2-hexyl parahydroxybenzoate and decyl-2-hexyl parahydroxybenzoate; esters or ethers of tetrahydrofurfuryl alcohol, such as oligoethyleneoxytetrahydrofurfuryl alcohol; and esters of citric acid or hydroxy-malonic acid, such as oligoethyleneoxy malonate.

It would not be beyond the scope of the invention to use a mixture of plasticizers.

Composition, use and process

As indicated above, the compositions of the invention comprise at least:

(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide,

(d) from 0% to 65% by weight of at least one filler.

According to one embodiment, the compositions of the invention comprise at least:

(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide,

(d) from 0% to 65% by weight of at least one filler,

(e) from 0% to 15% by weight of at least one plasticizer,

(f) from 0% to 30% by weight of at least one impact modifier.

According to one embodiment, the compositions of the invention comprise:

(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide,

(d) from 0% to 65% by weight of at least one filler, and

(e) from 0% to 15% by weight of at least one plasticizer,

the sum of constituents (a)-(e) being equal to 100%.

In particular, according to this embodiment, the compositions of the invention consist of:

(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide,

(d) from 0% to 65% by weight of at least one filler, and

(e) from 0% to 15% by weight of at least one plasticizer,

the sum of constituents (a)-(e) being equal to 100%.

According to another embodiment, the compositions of the invention comprise:
(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide,

(d) from 0% to 65% by weight of at least one filler, and

(e) from 0% to 30% by weight of at least one impact modifier,

the sum of constituents (a)-(e) being equal to 100%.

In particular, according to this embodiment, the compositions of the invention consist of:

(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide,

(d) from 0% to 65% by weight of at least one filler, and

(e) from 0% to 30% by weight of at least one impact modifier,

the sum of constituents (a)-(e) being equal to 100%.

According to yet another embodiment, the compositions of the invention comprise:
(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide, and

(d) from 0% to 65% by weight of at least one filler,

the sum of constituents (a)-(d) being equal to 100%.

In particular, according to this embodiment, the compositions of the invention consist of:

(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,

(b) from 0.1% to 10% by weight of at least one additive,

(c) from 0% to 70% by weight of at least one virgin polyamide, and

(d) from 0% to 65% by weight of at least one filler,

the sum of constituents (a)-(d) being equal to 100%.

According to one embodiment, the composition of the invention is different from a composition comprising 55% by weight of a copolymer with rigid polyamide blocks and recycled flexible polyether blocks (PEBA), 44.5% by weight of a polyamide 11 and 0.5% by weight of an antioxidant.

According to one embodiment, the composition of the invention is different from a composition comprising 90% by weight of a copolymer with rigid polyamide blocks and recycled flexible polyether blocks (PEBA), 9.5% by weight of a polyamide 11 and 0.5% by weight of an antioxidant.

According to one embodiment, the composition of the invention is different from a composition comprising 20% by weight of a copolymer with rigid polyamide blocks and recycled flexible polyether blocks (PEBA), 79.5% by weight of a polyamide 11 and 0.5% by weight of an antioxidant.

According to one embodiment, the composition of the invention is different from a composition comprising 99.5% by weight of a copolymer with rigid polyamide blocks and recycled flexible polyether blocks (PEBA) and 0.5% by weight of an antioxidant.

According to any one of the embodiments of the invention, the composition of the invention can be in the form present in the form of solid particles with a median diameter D50 of less than 20 mm, preferably between 0.1 and 10mm.

The inventors discovered, surprisingly, that the compositions of the invention presented better processability, compared in particular to compositions devoid of recycled polyamide elastomer. In particular, the compositions of the invention advantageously have a greater injection flow length compared to the same composition in which the polyamide elastomer is not recycled.

The invention thus relates, according to another of its aspects, to the use of a composition as defined above, to give said composition a greater injection flow length compared to the same composition in which the polyamide elastomer is not recycled.

As indicated previously, the compositions of the invention advantageously have sufficient properties to allow their use for high performance applications, and not only for lower performance applications such as street furniture or roads.

In particular, it has been demonstrated that the compositions of the invention make it possible to manufacture objects, in particular mono-materials, having good mechanical properties.

Advantageously, the compositions of the invention can also make it possible to maintain good elasticity (low tan δ at 23°C), mechanical properties (moduli, elongation at break) and an ability to adhere to different substrates similar to those of virgin polymers. .

Advantageously, the compositions of the invention can also make it possible to maintain a density and/or chemical resistance similar to those of virgin polymers.

This is why, according to another of its aspects, the present invention relates to the use of a composition as defined above for the manufacture of objects, in particular mono-materials.

According to another of its aspects, the present invention also relates to an object, in particular a mono-material, consisting of at least 30% by weight, preferably at least 50% by weight of a composition according to the invention.

It may in particular be a single-material object comprising at least two elements:

- at least a first element consisting of a first composition comprising by weight at least 30%, of at least one recycled polyamide elastomer as defined above,

- at least one second element consisting of a second composition comprising by weight at least 30% of at least one recycled polyamide elastomer as defined above,

said first and second elements being able to adhere at least partially to one another.

By “mono-material object” we must understand an object made up mainly of the same

material, in this case a recycled polyamide elastomer in both compositions.

In a first variant, the mono-material objects can be without being limited to these:

An electronic item, in particular a watch, a phone case, headphones, earphones, a speaker, a keyboard, a mouse, a phone charger,

an article of clothing, in particular a jacket, pants, t-shirt, socks

an optical article, in particular prescription glasses, sunglasses, children's glasses, sports glasses and a ski mask, augmented reality/virtual reality glasses.

a household appliance, in particular a small household appliance, a household appliance accessory (bowl, mixing paddle, food container), a water bottle, a food container,

a cosmetic item, in particular cosmetic packaging such as a bottle, a perfume, makeup packaging, skincare packaging, a presentation item, a hairbrush,

a sporting item, in particular a surfboard (and its accessories such as leash or fins), a bicycle, bicycle item such as saddle or pedal, a helmet, a ski boot, skis, poles ski, a ski binding and a snowboard (excluding metal), a golf club, any type of racket in particular a tennis racket, protective equipment such as shin guard, elbow pad, etc., a hockey stick (on grass and ice), a roller skate, diving fins,

an item of luggage, in particular a suitcase, a backpack and a handbag

an item of stationery, especially pens.

a toy,

furniture, and

parts for a motor vehicle such as for example an airplane, a drone, an aircraft, an electric bicycle, a moped, a motorcycle, a side car, a car, a van, a tractor, a truck, a bus, a coach, a snowmobile, a half-track, a bulldozer, a snow groomer and an assault tank.

In one embodiment, at least 50% by weight of recycled polyamide elastomer is present in each of the two elements relative to the total weight of the composition of each element.

In other words, the sum by weight of recycled polyamide elastomer in the first element and recycled polyamide elastomer in the second element is at least 50% relative to the total weight of the two compositions of each element.

In another embodiment, the matrix of each of the two elements (fillers and additives excluded) is made up of 60% by weight, advantageously 80% by weight, preferably 100% by weight of recycled polyamide elastomer.

The term “element” designates each of the things whose combination, the union forms another thing, a whole, namely in the present invention a mono-material object.

In particular, an element designates a component, a component, a constituent, a piece, a part, a piece or unit which constitutes the mono-material object.

The expression “said first and second elements being able to adhere at least partially to one another” means that said first and second elements may or may not adhere to one another.

In one embodiment, said first and second elements do not adhere to each other.

In another embodiment, said first and second elements adhere to each other, at least partially, in particular completely.

The term “adheres” means that said first and second elements are attached to each other or applied against each other, at least partially and in particular by gluing, clipping, overmolding, thermoforming, screwing, sewing, welding or riveting.

It is obvious that said first and second compositions which comprise a recycled polyamide elastomer may also comprise additives and, optionally, impact modifiers and/or plasticizers and/or fillers as defined above.

According to one embodiment, the invention also relates to a method of manufacturing an object using solid particles as defined above, by remelting said particles then shaping an object by extrusion, molding or blowing of the particles melted.

The invention also aims to protect an object, in particular a single material, capable of being obtained by such a process. It may in particular be a single-material object as defined previously.

According to yet another of its aspects, the invention aims to protect an extruded, molded or blown part, for example an injection molded part, a continuous fiber composite, a film, a fiber, of a thread or filament.

According to one embodiment, the invention relates to a process for manufacturing a composition as defined above, comprising at least the following steps:

a) Dispose of post-industrial waste and/or post-consumer waste, in particular as defined above,

b) Grind said post-industrial waste and/or said post-consumer waste,

c) Optionally, carry out granulation of the ground materials obtained at the end of step (b),

d) Prepare said composition, for example using an extruder.

According to one embodiment, step d) consists of preparing said composition using an extruder, preferably a twin-screw extruder or a co-kneader, to form granules, an extrudate or a powder.

Alternatively, one can proceed to the manufacture of a composition of the invention by carrying out a pre-mixing step (coarse homogenization) of the solid particles as defined previously before the transformation step. This pre-mixing step is generally carried out at a temperature lower than the melting temperature of said solid particles.

The invention will be explained in more detail in the examples which follow.

Unless otherwise stated, the percentages are expressed in the following by weight relative to the total weight of the composition.

There represents the complete NMR spectrum in a mixture of HFIP/CD2Cl2 solvents (in an HFIP/CD2Cl2 ratio of 1/3) of PEBA n°1 of the examples (below spectrum: pristine PEBA n°1 and top spectrum: PEBA n° 1 recycled).

There represents an enlargement of the NMR spectrum of the in the region 1.85 ppm – 0.5 ppm (below spectrum: virgin PEBA n°1 and top spectrum: recycled PEBA n°1).

There represents an enlargement of the NMR spectrum of the in the region 10.5 ppm – 5.5 ppm (below spectrum: virgin PEBA n°1 and top spectrum: recycled PEBA n°1).

There represents the complete NMR spectrum in a mixture of HFIP/CD2Cl2 solvents (in an HFIP/CD2Cl2 ratio of 1/3) of PEBA n°2 of the examples (below spectrum: pristine PEBA n°2 and top spectrum: PEBA n° 2 recycled).

There represents an enlargement of the NMR spectrum of the in the region 10.5 ppm – 5.7 ppm (below spectrum: virgin PEBA n°2 and top spectrum: recycled PEBA n°2).

There represents a superposition of the FTIR infrared spectra in ATR mode of PEBA n°1 of the examples (in gray: virgin PEBA n°1 / in black: recycled PEBA n°1).

There represents an enlargement of the ATR spectra of the in the region 1820 – 1570 cm-1.

Examples

The examples in tables 1 and 2 below are obtained from the following PEBA n°1 and PEBA n°2.

PEBA n°1: PEBA copolymer comprising blocks of PA 11 with a number average molar mass of 1000 g/mol and blocks of flexible PTMG with a number average molar mass of 1000 g/mol with a hardness of 40 Shore D as measured after 3s according to the ISO 868:2003 standard. This PEBA includes 0.42% of additives (namely 0.34% by weight of a phenolic antioxidant (Irganox® 1010 marketed by BASF) and 0.08% by weight of a phosphite type antioxidant (Irgafos® 126 marketed by BASF)).

PEBA No. 2: PEBA copolymer comprising rigid blocks of PA 12 with a number average molar mass of 4000 g/mol and blocks of PTMG with a number average molar mass of 1000 g/mol, with hardness 63 Shore D as measured after 3s according to the ISO 868:2003 standard. This PEBA includes 0.42% of additives (namely 0.34% by weight of a phenolic antioxidant (Irganox® 1010 marketed by BASF) and 0.08% by weight of a phosphite type antioxidant (Irgafos® 126 marketed by BASF)).

In their virgin form, the molar ratios of the methyl functions at the end of the chain relative to the secondary amides are 0.003 and 0.002 for PEBA No. 1 (virgin) and PEBA No. 2 (virgin) respectively. No line corresponding to the formate groups is observed.

In order to simulate the thermo- or photo-oxidative aging of the PEBAs during their life, aging in an oven at 140°C in air for 24 hours was carried out on PEBAs no. 1 and no. 2. This aging is representative of the degree of oxidation measured on PEBA at the end of its life or having been used several times (in other words of a recycled PEBA within the meaning of the invention).

After aging, the molar ratio of the formate and methyl functions at the end of the chain relative to the secondary amides are 0.070 and 0.020 respectively in aged (recycled) PEBA No. 1.

After aging, the molar ratio of the formate and methyl functions at the end of the chain relative to the secondary amides are 0.002 and 0.004 respectively in aged (recycled) PEBA No. 2.

The molar quantities of these different functions were measured by NMR according to the protocol defined in the description (namely by dissolving 20 mg of polymer in 0.7 mL of HFIP/CD2Cl2 solvent, with an HFIP/CD2Cl2 ratio of 1/3) .

The injection flow length was measured on an injection press (ENGEL VICTORY 500, 160T) equipped with a spiral mold (spiral flow test in English) with the following parameters:

Mold temperature: 40°C

Material holding pressure: 900 bar

Temperature profile for PEBA n°1: 200/220 °C

Temperature profile for PEBA n°2: 220/240 °C

Flow rate: 57 cm ³ /s

Cooling time: 20 s

The test is carried out by injecting the molten polymer through the central core which directly feeds the spiral 20 mm wide, 2 mm thick and having a maximum length of 1280 mm. The spiral mold is mirror polished.

The flow length values reported in the table below correspond to the average of the ten tests carried out for each sample.

This measurement makes it possible to characterize the processability of the compositions.

The peel was measured after overmolding on a cold insert (injected the day before) of PEBA n°1 injected on an injection press.

Injection parameter of PEBA inserts n°1:

Insert thickness: 2 mm

Mold temperature: 40°C

Material injection pressure: 370 bar

Material holding pressure: 600 bar

Temperature profile: 200 / 220

Cooling time: 8 s

The following parameters were used to overmold the EC 2 and EI 2 on the PEBA n°1 inserts placed in the mold manually before each overmolding:

Mold temperature: 40°C

Material holding pressure: 600 bar

Temperature profile for PEBA n°2: 220/240

Cooling time: 10 s

The peeling force measurements were carried out using the so-called “T-peel” peeling method according to the NF EN ISO 11339 standard and under the following conditions:

- Peeling over a variable length depending on the stretchability of the peeling arms: 150 mm to 400mm.

- Test speed of 50 mm/min.

- Free angle avoiding any contact between the test piece and the upper jaw of the dynamometer.

- Five test pieces per reference.

- Sensor: 1kN.

- Dynamometer: Synergy 200H.

This measurement makes it possible to characterize in particular the durability of the compositions.

The composition EI 1 according to the invention has a flow length significantly greater than that of the comparative composition EC 1.

This means that the composition EI 1 according to the invention has better processability than the comparative composition EC 1.

In particular, it will advantageously be possible to inject thinner parts and/with better definition using an EI 1 composition according to the invention.

The composition EI 2 according to the invention has a flow length significantly greater than that of the comparative composition EC 2.

This means that the composition EI 2 according to the invention has better processability than the comparative composition EC 2.

In particular, it will advantageously be possible to inject thinner parts and/with better definition using an EI 2 composition according to the invention.

The composition EI 2 according to the invention also has better adhesion after overmolding than the comparative composition EC 2.

This means that the parts overmolded with an EI 2 composition according to the invention will advantageously be more durable than those overmolded with a comparative EC 2 composition.

Claims (26)

Composition comprising at least:
(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,
(b) from 0.1% to 10% by weight of at least one additive,
(c) from 0% to 70% by weight of at least one virgin polyamide,
(d) from 0% to 65% by weight of at least one filler. Composition according to claim 1, characterized in that said molar ratio of functions resulting from oxidation reactions relative to secondary amide functions is between 0.0005 and 0.3. Composition according to any one of the preceding claims, characterized in that said molar ratio of the formate functions relative to the secondary amide functions is between 0.0005 and 0.2, in particular between 0.001 and 0.08, in particular between 0.005 and 0.08. 0.05. Composition according to any one of the preceding claims, characterized in that said molar ratio of the methyl groups at the end of the chain relative to the secondary amide functions is between 0.0005 and 0.2, in particular between 0.001 and 0.08, in particularly between 0.005 and 0.05. Composition according to any one of the preceding claims, characterized in that said
molar ratio of the primary amide functions relative to the secondary amide functions is between 0.0005 and 0.1, in particular between 0.001 and 0.08, in particular between 0.005 and 0.05. Composition according to any one of the preceding claims comprising:
(a) from 30% to 99.9% by weight of at least one recycled polyamide elastomer having functions resulting from oxidation reactions chosen from formate functions, methyl groups at the end of the chain, primary amides, nitriles , alkenes, formamides, carboxylic acids, aldehydes, imides, alcohols and their mixtures, in a molar ratio relative to secondary amide functions greater than that of the same virgin polyamide elastomer,
(b) from 0.1% to 10% by weight of at least one additive,
(c) from 0% to 70% by weight of at least one virgin polyamide, and
(d) from 0% to 65% by weight of at least one filler,
the sum of constituents (a)-(d) being equal to 100%. Composition according to any one of the preceding claims, characterized in that said recycled polyamide elastomer is a copolymer with rigid polyamide PA blocks and flexible blocks. Composition according to the preceding claim, characterized in that the polyamide of the rigid block of said recycled polyamide elastomer has a C/N ratio greater than 6.5, advantageously greater than 7.5, preferably greater than 8.5. Composition according to any one of claims 7 to 8, in which said flexible block comprises at least one block chosen from: polyether, polyester, polydimethylsiloxane, polyolefin, polycarbonate, and their mixtures or copolymers. Composition according to any one of claims 7 to 9, in which said flexible block comprises at least one PE polyether, preferably chosen from PTMG, PPG, PO3G and/or PEG. Composition according to any one of claims 7 to 10, in which said flexible block comprises at least one PES polyester, preferably chosen from polyester diols, poly(caprolactone) and polyesters based on fatty acid dimers. Composition according to any one of claims 7 to 11 in which said at least one copolymer comprises from 45 to 75% by weight of flexible polytetramethylene glycol (PTMG) blocks, preferably from 50 to 70% by weight of PTMG blocks, on the total weight of copolymer. Composition according to any one of claims 7 to 12, in which said PA polyamide block comprises at least one of the following polyamide units: 6, 66, 610, 612, 613, 129, 913 PA1010, PA1012, PA11, PA12, PA6 /12, and their mixtures or copolyamides. Composition according to any one of claims 7 to 13, in which said at least one copolymer comprises a copolymer with rigid polyamide blocks and flexible polyether blocks (PEBA). Composition according to any one of claims 7 to 14, in which said at least one copolymer is chosen from the following PEBAs: PA6-PTMG, PA1010-PTMG, PA1012-PTMG, PA11-PTMG, PA12-PTMG, PA6/12- PTMG, PA66-PTMG, PA613-PTMG, PA129-PTMG, PA913-PTMG and their mixtures. Composition according to any one of claims 7 to 15, in which the ratio by weight of the PA blocks to the flexible blocks is in the range from 0.3 to 10, preferably from 0.3 to 6, preferably from 0 .3 to 3, preferably 0.3 to 2. Composition according to any one of the preceding claims, characterized in that it comprises from 0.1 to 50% by weight of at least one virgin polyamide, relative to the total weight of the composition, for example from 0.2 to 35% by weight, for example from 5 to 25% by weight, said virgin polyamide being preferably chosen from homopolyamides, copolyamides, and copolymers with polyamide blocks and polyether blocks (PEBA) or mixtures thereof. Composition according to any one of the preceding claims, characterized in that said additive is chosen from a catalyst, an antioxidant, a heat stabilizer, a UV absorber, a light stabilizer, a lubricant, a nucleating agent, a dye, a wax and mixtures thereof. Composition according to any one of the preceding claims, characterized in that it is in the form of solid particles with a median diameter D50 of less than 20 mm, preferably between 0.1 and 10 mm. Use of 30% to 99.9% by weight of at least one recycled polyamide elastomer as defined according to any one of claims 1 to 16 in a composition as defined according to any one of claims 1 to 19, for give said composition a greater injection flow length compared to the same composition in which the polyamide elastomer is not recycled. Use of a composition according to any one of claims 1 to 19 for the manufacture of objects, in particular mono-materials. Object, in particular mono-material, consisting of at least 30% by weight, preferably at least 50% by weight, of a composition as defined according to any one of claims 1 to 19. Process for manufacturing an object using solid particles as defined in claim 19, by remelting said particles then shaping an object by extrusion, molding or blowing the molten particles. Object, in particular mono-material, capable of being obtained by the process of claim 23. Object according to claim 24, characterized in that it is an extruded, molded or blown part, for example an injection molded part, a continuous fiber composite, a film, a fiber, thread or filament. Process for manufacturing a composition as defined according to any one of claims 1 to 19, comprising at least the following steps:
a) Dispose of post-industrial waste and/or post-consumer waste,
b) Grind said post-industrial waste and/or said post-consumer waste,
c) Optionally, carry out granulation of the ground materials obtained at the end of step (b),
d) Prepare said composition, for example using an extruder.